Adjusting device, in particular electrical condenser



Jan. 4, 1938. K. HENGEL 2,104,160

ADJUSTING DEVICE, IN PARTICULAR ELECTRICAL CONDENSER Filed Jan. 23, 1934 2 Sheets-Sheet 1 23 25 Z] 2 1 24 P 11 1 19 t i 1o 20 3] i a 5 7 a? a I z I 27 i i i I3 I i 6 ":c: :::1;: f ii2? l I "mI'::.:::.:.:;':::.t::

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Jan.4, 1938.- K. HENGEL- A'QJUS'ITING DEVICE, IN PARTICULAR ELECTRICAL CONDENSER Filed Jan. 23, 1954 Z Sheets- Sheet 2 0 vinfor:

Patented Jan. 4, 1938 UNITED STATES ADJUSTING DEVICE, IN PARTICULAR ELEC- TRICAL CONDENSER Karl Hengel, Berlin, Germany Application January 23, 1934, Serial No. 707,935 In Germany January 27, 1933 14 Claims.

With electrical variable condensers and the like, for instance, such used in radio receiving sets, in many cases the rapid and extremely accurate adjustment of a definite value of the capacity is called for. For that purpose it has been suggested in known rotary or variable condensers to combine a rough adjusting system with a system for fine adjusting, electrically connected in parallel. Generally, themanipulation of the movable fine adjusting plate is effected through a special handle co-ordinated to the knob for rough adjustment. However, arrangements have already been suggested, in which the sets of plates or segments of the condenser for rough 15 and fine adjustment may be manipulated by means of a single adjusting knob, which was ren- -dered possible by the provision of a no-load coupling or lost motion connecting device which will admit of the adjustment of the set of plates for l0 fine adjustment within the limits oi its play,

without causing -a change of adjustment of the set of plates for rough adjustment efiected previously by means of the same adjusting handle.

These known arrangements with no-load couplings, however, did not gain any practical importance. hand to the circumstance, that the play of the no-load coupling employed was not suificiently small, in order to effect the adjustment of the condenser in a rapid and simple manner, as in the case of the ordinary rotary condensers with out fine adjustment.

Moreover, through the large play in coupling present with the known arrangements, the prac- 235 tical manipulation of the condenser, if the latter was employed in radio apparatus, was rendered difficult to such an extent, that the industry declined to make use of such condensers, while for the fine adjustment transmission gearing was employed to a growing extent. On the other hand, the known adjusting devices with a special coupling for the rough and fine adjustment by manipulation of a single knob, were not as yet sufiiciently simple in construction and 4-3 required much space.

As regards the known rotary condensers with transmission gearing, it is possible however to obtain a very accurate adjustment of the operating value desired each time by making use of a high ratio of gearing. But, besides, the complicated mode of execution dependent on a high ratio of caring, there is the drawback, that with manipulation by means of a single knob a great many rotations of said knob are necessary, in #5 order to pass from one condenser adjustment to another more remote condenser adjustment. Therefore it was again endeavored to choose the ratio of gearing with such arrangements not too great at the expense of the accuracy of adjustment, and a compromise was made upon choos- This may be attributed on the one ing the magnitude of such ratio, which will make allowance for the two oppositely directed moments, without however fully satisfying the desires, neither in the one direction nor in the other.

In order to facilitate the fine adjustment of a condenser without the use of a special transmission device, adjusting devices with a no-lcad coupling, as already mentioned, have been suggested. m

The aggravation of the manipulation oi the condenser caused by the large play in coupling with known devices of this type, above all comsisted in that withthese arrangements the rap adjustment to a definite operating value wi. the aid of a scale is impeded and that certain prescriptions had to be observed during adjustment. Thus with the use of known adjusting de vices with a large coupling play in radio receiving sets with a station scale a definite station 20 can only be selected rapidly and easily, ii. the said station scale has been gauged for stations simply by advancing the adjusting pointer, whereby the selection of a certain station with the aid of the scale can be efiected only by a 2-1; forward rotation. In the same manner, of course, also the calibration by returning the adjusting v pointer backward could be carried through, whereby the selection of a certain station on the scale' could be effected only by a reverse rotation. By making use of two scales, o of which is calibrated for forward rotation the other one for reverse rotation, the zero.. prior to each new rough adjustment, du: which the direction of rotation must be chrm means of two scales would be rendered exceed ingly difiicult.

The invention has for object to obviate ti se deficiencies of the known adjusting deidces no-load coupling and with a rough and fine justing arrangement operated by a single no ing knob.

According to the invention the mag". the adjusting range limited by stops or the with adjusting devices, particularly with el cal rotary condensers having a coupling, a will render possible the manipulation of a and fine adjusting member or by of a single adjusting knob, is c osen namely with a rotary device ahent te degrees and less, that the immediate a of the desired value of operation, p with the aid or an adjusting scale, is possible during the advance and return mo ment of the adjusting knob in an equally aim manner.

Through the choice of a very small range of movement of the fine adjusting member, by the provision of stops, for instance the flanks of a no-load coupling, a manipulation of the fine adjusting member is obtained, which is just as sim ple as that with the known ordinary adjusting devices without any special coupling and fine adjustment. It must be considered in this respect, that the setting of an adjusting device with the aid of an adjusting scale to a definite value on the scale will be eiiected in general only in a more or less crude manner, since such adjustment is dependent on numerous influences, as for instance, lack of practice, parallax, rapidity of eirecting the adjustment; distribution of shades ,with unfavorable illumination and the like.

As is well known, the adjustment of a radio receiving set through the commonly technically untrained listener is efiected in such a manner, that in the first place the desired station is selected with the aid of the station by means of the eye in a relatively short time.

But such adjustment is effected only in a rather crude manner, whereupon fine adjustment is obtained with the aid of the ear by carrying out slight reciprocating movements about the point chosen by rough adjustment. A purely optical adjustment simply with the aid of the eye by means of the station scale would be futile with a radio receiving set for the reason, that very seldom a quite precise agreement of the mark of the scale allotted to a distinct sending station will be present at this junction with the best audibility 0f the sending station. There may occur deviations amounting to several angular degrees. For that reason it is absolutely necessary to carry out adjustment with the aid of the eye only quite crudely and to effect fine adjustment through the ear subsequently. Here very often, particularly with adjusting devices having a small ratio of gearing, the selection among the special adjustments lying frequently rather close to the rough adjustment, is effected subsequent to the rough adjustment through the eye simply through the ear only, because the desired sending station can be obtained in this manner more easily and rapidly than through a purely optical selection. But if the range of inaccuracy of adjustment caused by the adjusting operation as such coincides with the small range of inaccuracy remaining yet through the reduced play of the coupling, Oioif the former will constitute a substantial portion thereof, any injurious effect through the play of the coupling cannot occur'at all, on the contrary the practical use of the improved adjusting device is just as simple as that of the known adjusting devices without special coupling and conse-' quently also without the possibility of fine adjustment.

Therefore, with the rather minute play of the coupling of an adjusting device with a no-load coupling according to the invention advantages are obtained, which will not be present with the known arrangements of this type having a large play of the coupling.

Beyond this, the invention has for its object the suitable construction of an adjusting device with adjusting knob for the automatic rough and fine adjustment carried out in the manner described. This improved construction is obtained according to the invention in that the member for fine adjustment of the adjusting device is driven in the course of the power transmitting driving-parts by way of a friction coupling and that the motion of said member is being limited by means of two stationary stops. low various modes of construction.

On the accompanying drawings the invention is illustrated by way of example and Figure 1 is an electrical rotary condenser according to the invention partly in section, as seen from the side;

Figure 2 is a rear view of said condenser;

Figure 3 illustrates the scale of said condenser on a reduced scale;

Figure 4 represents a notched disc of said condenser, likewise on a reduced scale;

Figure 5 is a diagrammatic view of another modification of the condenser according to the invention;

Figure 6 represents a portion of the transmission gear of the modification according to Figure 5;

Figure 7 is a further modification of a condenser according to the invention without transmission gear, as seen from the side, partly in section;

Figure 8 is a rear view of the modification according to Figure 7; and

Figure 9 is a rotary condenser according to the invention with transmission gear.

With the modification of the improved rotary or variable condenser illustrated in Figure 1 the stationary set of plates or segments carried by the support I of the condenser 2 for rough adjustment is designated by 3 and the movable set of plates by i. The movable plates or segments From this foli are mounted on a hollow shaft 5 within which a spindle 6 is journaled. On the front end of the spindle 6 is mounted a disc i, which is in frictional engagement with a disc 8 of smaller siz e which latter is actuated by a turning kn'ob 9. The disc 7 is provided with a hand or pointer it moving in front of a scale II, as follows particularly from Figure 3. Upon the rearward extremity oi the spindle 6 is arranged a short sleeve 62, being rigidly connected with the spindle 8 by means of a, set screw i3 with sunk head. In contradistinction the hollow shaft 5 of the rotor is adapted to easily rotate about the spindle 6 and it is provided on its rear end with an extension M which engages with play a slot IS in the sleeve i2, so that a no-load coupling i6 is produced.

On the sleeve i2 is arranged in frictional connection a further'sleeve ll, from which a flat tongue i8 projects, which is provided on its surface with an insulated coating I9, which cooperates capacitatively with a counter-layer or coating 20 forming a condenser 24 for fine adjustment. The counter-coating 29 is formed in a simple manner by one shank of an angular piece 22 of sheet metal, the other shank 23 of which is secured to the support 9 of the condenser for rough adjustment 2 by means of one of the known nuts 25, serving for the assemblage of the stator. The movement of the tongue i8 is limited through a stop pin 25 of insulating material. In order to prevent an electrical contact of both the electrodes i8 and 2d of the auxiliary condenser, a projecting non-conductive limiting pin 26 is provided on the electrode 28.

.Figures 1' and 2 therefore illustrate a rotary condenser, which forms the combination of an ordinary rotary condenser 2 as rough adjusting system, the plates 3 and i of which are moved parallel to each other, with a condenser 2| for fine adjustment, the plates 98, 26 of which are moved in a direction perpendicular to their superficial dimensions.

modification according to Figure 1 in the course of the power transmitting driving-parts 8, 8, I, 8, l2, 8 for the rotor 4 of the condenser, 2 101 rough adjustment, which are actuated by the same knob 8, the no-load coupling or lost motion connecting device i8.

With multi-condensers for multi-circuit receiving sets for wireless telephony the described arrangement may be multiplied and the spindle 8 may be continuous, as such is indicated bybroken lines in Figure 1.

Furthermore, a disc 28.may be mounted oh the rotor shaft 8 of the condenser 2 for rough adjustment (Figure 1), as such is illustrated in detail in Figure 4. Said disc may be provided with notches distributed thereon in correspondence with the capacities to be selected or with the sending stations the signals of which are to m received respectively, which notches are engaged during the rotation of the disc by a positioning pin-8i being subjected to the act-ion of a spring 30, without however completely hindering the rotation. The said notches facilitate the rapid adjustment of the condenser. They will define certain capacities of the condenser 2 for rough adjustment, while through the fine adjustment with the aid of the auxiliary condenser 2| intermediate stages may be selected, which are ap proximate to or lie between the values obtained by rough adjustment.

The sleeve i2 is provided in the modification illustrated in Figure 1 with a steep thread 32 while the sleeve I I slipped over it, is formed as appurtenant screw-nut.

By this an axial movement of the sleeve I! is obtained at the same time with the rough adjustment, which will efiect a parallel displacement of the electrode l8 of the auxiliary condenser !I in respect of its counter-electrode 20, so that these electrodes will register more or less. The described construction in an extremely simple manner allows a fine adjustment of constant sensitiveness with regard to the value of the coarse adjustment selected each time. The final adjustment being obtained thereafter by slight turning movements of the-knob 8 in either direction in the manner explained already.

The magnitude of the play of coupling of the no-load coupling IS with the modification according to Figures 1 to 3 is chosen rather small. Figure 3 illustrates the rather acute angle of rotation is, admitted by the play of the no-load .coupling'during a rotary movement up to the contact of the flanks of said no-load coupling each time. Owing to this slight play of coupling the selection of a definite rough value of capacity with the aid of the adjusting scale II is rendered possible in an equally simple manner both by turning the knob 8 to the right and left hand side and .the manipulation of the novel condenser is just as simple as that of the ordinary condensers, in which there is not made any provision for fine adjustment.

The mode of operation of the novel rotary condenser according to Figures 1 to 3 may be more fully explained in employing it with a receiving set for wireless broad-casting, for which condensers of this class are preferably adapted and intended. a

When selecting a certain station the knob 8 is turned until the pointer 10 (Figures 1 and 3) reaches the desired spot on the scale ll. During such rough adjustment simply the rotor l of the condenser 2 for rough adjustment is moved, while the electrode "for fine adjustment of the auxiliary condenser 2| abuts against one of the stops 28 or 28 and remains inoperative without hindering the rotary movement of the set of plates 4 for rough adjustment thanks to the, frictional connection 21. Subsequent to rough adjustment now by a slight reciprocatory turning of the knob 8 by gradually decreasing. pendulum movements about the position of the pointer selected at first in a crude manner, the selection of the desired receiving value is carried through. until optimum reception oi the signals is obtained. Here the no-load coupling l8 will come into the action, which causes a variation of the adjustment 'of the condenser II for fine adjust ment. By operating the rotary condenser in the manner customary with the adjustment of receiving sets, the fine adjustment is automatically effected subsequent to each desired rough adjustment.

If an adjusting device with transmission gear is used, a special no-load coupling may be dispensed with when the said transmission gear possesses a lost motion run or such is applied to it. In Figure 5- a rotary condenser 38 is illustrated, the rotor 44 of which mounted on the shaft 48 is driven by way of the transmission gears 84, II. The intermeshing gears ll, 38 represented once more in Figure 6 in front view ofi'er a certain lost motion run through a play existing between the teeth.

The driving shaft 88 for the small gear 34,

on one extremity of which the operating knob 31 is mounted, carries on its opposite extremity a tongue 38 by forming a friction coupling 38 in frictional. connection with it, which in the same manner as described above, will iorm with the counter-electrode 48 an auxiliary condenser II, which serves for fine adjustment. The deviation of the tongue 39 is limited on the one hand by the counter-electrode l0 and on the other hand by a stop pin 82. The mode of operation of the modification according to Figure 5 should be obvious at once, since the above explanations in respect of the mode of operation of the condenser according to Figures 1 to 3 will also apply to this case. When using the invention with adjusting devices the driving means of which operate with play or have elastic flexibility, i. e. have a drivingshaft which warps. that is to say, when employlng the invention in connection with adjusting devices the drive of which has mechanical allowances, profitable use may be made of such allowances as, according to the invention, they cannot exert any disturbing influence on the fine adjustment, whereas, in contradistinction to this, hitherto such mechanical allowances were highly injurious to the fine adjustment of condensers used in wireless telephony.

Figures 7 and 8 show a rotary condenser of the customary mode of construction in side and rear view, in which simply the shaft 41 driven by the turning knob 46 is somewhat longerat its rear end than usually. Over this extremity is slipped the tongue 88, which is bent below to form a-spring sleeve 59 (Figure 8). Through the resiliency of the sleeve 69 a good frictional fitting is obtained providing a friction coupling 58 between the shaft 51 and the sleeve 69.

At its upper end, the tongue 68 is provided with an electrode 5|, which cooperates capacitively with a counter-electrode 52 forming an auxiliary condenser 53. Said counter-electrode 52 is carried by one shank of an angular member 56, the other shank 55 of which serves as attaching means to the frame of the condenser 55. The contact of the two electrodes til and 52 is prevented by an insulating pin 56 and the retrograde movement of the tongue 18 is limited by a stop pin 51 of insulating material. The pins 56 and 571 are located closely opposite so that the maximum sway of the tongue d8 is only very small, in the example illustrated below ten angular degrees. The chief condenser Q5 and the auxiliary condenser 53 are connected electrically in parallel in known manner.

With the modification according to Figures 7 and 8 is arranged in the course of the power transmitting driving-parts for the electrode 5i for fine adjustment a friction coupling 5d, but any no-load coupling is missing here. However the arrangement in this instance is such that upon manipulating the adjusting knob es, which will cause an increase of the capacity of the condenser 55 for rough adjustment by turning the set of plates 53 of the rotor in the direction of the arrow shown in Figure 8, the movement of the electrode 5i for fine adjustment takes place in the sense of the arrow shown there in a direction, in which the capacity of the auxiliary condenser 53 will decrease, since the electrode iii of the latter will recede fromits counter-electrode 52. At an opposite turning of the adjusting handle 16 the same applies in a reverse manner.

Through this arrangement it is possible that after having effected the rough adjustment of the device to a definite operating value during fine adjustment within the range of the sway of the-tongue 38 defined by the limiting pins 5E, 57, the movement of the condensers 35 and 53 respectively for rough and fine adjustment is effected in a manner, in which the rough and fine value of the capacity will change in the reverse sense and both values will partly compensate one another. The compensation of the capacity is chosen so great, that the change of the capacity still remaining here during the turning within the small range for fine adjustment defined bv the stationary stops 5? (Figure 8), will just render possible a commodious fine adjustment to all practically obtainable fine values such as for tunirigtvireless receiving sets.

With the arrangement according to Figure 9 the principle of fine adjustment through partial compensation of the change capacity of the condenser for rough and fine adjustment described above, within the small range for fine adjustment again defined by means of stationary limiting agents, is likewise resorted to. In this instance again a condenser is concerned having a transmission gear. The rotor 65 of the condenser tiii is driven by the knob 62 by way of the shaft 68, and the frictionally engaging discs 66 and 55.

On the right hand end of the shaft 63 is mounted again a tongue 67 in frictional connection by forming a friction coupling 6%, said tongue ca rrying an electrode 63, which will capacitively cooperate with the counterelectrode 69. The two electrodes 68 and 69 again form an auxiliary condenser ID. The electrical connections of the two condensers and I0 electrically connected in parallel, are not shown, since these are obvious. The modification according to Figure 9 has the advantage over that according to Figure '7, in that in consequence of the power transmitting device 64, upon manipulating the adjusting knob 62, the rotary movement of the electrode 68 serving for the fine adjustment is greater than the rotary movement of the rotor 6| serving for rough adjustment. The mode of operation of the condenser according to Figure 9 is obvious in consideration of the explanations rendered above, particularly in respect of Figure '7.

ihe arrangement of the novel adjusting device may m effected in a manner varying from the specification, without departing from the scope of the invention.

I claim:

1. In a device of the class described in combination a primary condenser and a secondary condenser, a frame carrying fixed plates of said primary condenser and a fixed armature of said secondary condenser, a shaft journalled in said frame. a hollow shaft rotatably mounted on said shaft and carrying movable plates of said primary condenser, a sleeve fixed to one end of said shaft, a lost motion connection between said sleeve and said hollow shaft, a support frictionally connected to said sleeve and carrying a movable armature of said secondary condenser, stops on said frame for limiting the movements of said movable armature and an adjusting knob for turning said shaft and said hollow shaft.

2. In a device as set forth in claim 1, a setting shaft rotatably mounted in said frame and carrying said adjusting knob, a power transmission disc of small diameter fixed on said setting shaft, an-- other power transmission disc of large diameter fixed on said shaft and driven by said disc of small diameter and a notched disc fixed to said hollow shaft having notches in its periphery in which engages a spring actuated bolt connected to said frame.

3. In a device as set forth in c.'-aim 1 a steep helical notch provided onsaid sleeve and a corresponding means providedin a hub of said support surrounding said sleeve, said means engaging said notch to obtain an axial movement of said support simultaneously with the rotation of said movable plates of the primary condenser.

4. In a device of the class described the combination with a condenser of the rotary type comprising fixed plates mounted in a frame and movable plates fixed on a shaft journalled in said frame and carrying an adjusting knob, of a second condenser comprising a movable and a fixed armature, said movable armature being frictionally connected to said shaft and said fixed armature being mounted on said frame, and stops carried by said frame in a slight distance from each other for limiting the movements of said movable armature, the arrangement being such that during the fine adjustment one of the condensers moves to increase its capacity and simultaneously the other condenser moves to decrease its capacity and vice versa, so as to partially compensate the changes in capacity of both condensers.

5. In a device of the class described the combination with a condenser of the rotary type comprising fixed plates mounted in a frame and movable plates fixed on a shaft journalled in said frame, of a second condenser comprising a movable and a fixed armature, a second shaft journailed in said frame frictionally connected to a support for said movable armature, a power transmission disc oi small diameter mounted on said second shaft, a power transmissiondisc oi large diameter fixed to said first mentioned shaft and driven by said power transmission disc of small diameter, an adjusting knob fixed to said second shaft for moving the rotatable plates of said rotary condenser as well as said support for said movable armature of said second condenser, and stops carried by said frame at a slight distance apart for limiting the movements of said movable armature, the arrangement being such that during the common operation 'one of the condensers moves to increase its capacity and simultaneously the other condenser moves to decrease its capacity and vice versa, so as to partially compensate the changes in capacity of both condensers.

6. In a device of the character described, comprising, a rough adjusting member, a fine adjusting member, coupling means between said rough and fine adjusting members with upper and lower limits to allow of movement of said fine adjusting member between said limits and only within predetermined narrow limits of the range of movement on said rough adjusting member, substantially equally for any position of said rough adjusting member, and a common actuating member for said adjusting members.

7. The combination of a main condenser and a vernier condenser, a first movable element for adjusting the capacity of said main condenser, a second movable element for'adjusting the capacity of said vernier condenser, a common actuating member for said condensers, coupling means between said movable elements with upper and lower limits to allow of movement of said second element between said limits and only within predetermined narrow limits of the range of movement of said first element, substantially equally at any position of said first element.

8. The combination of a main rotary condenser and a vernier condenser, said condensers having movable elements for adjusting their capacity, a common actuating member for adjusting said condensers, coupling means between said movable elements with upper and lower limits to allow of adjustment of said vernier condenser between said limits and only within predetermined narrow limits of the adjusting range of said main condenser, substantially equally at any adjusting position of said main condenser, said limits comprising less than 10 angular degrees for a useful adjusting range of degrees of said main condenser.

9. In an adjusting device for a variable condenser or the like, a rough adjusting member, a fine adjusting member, coupling means between said rough and fine adjusting members, said coupling means having a play with upper and lower limits comprising a small fraction of the total useful range of movement of said rough adjusting member to allow of independent move ment of said fine adjusting member within said limits and only within predetermined narrow limits of the range of movement of said rough adjusting member, substantially equally for all positions of said rough adjusting member, a common actuating member for said adjusting members, and scale means cooperating with said actuating member for said rough adjusting r actuating member to indicate the pesiticu said actuating member.

10. In an adjusting device for a vari denser or the like, a rough adjusting fine adjusting member, coupling means between said rough and fine adjusting members, said i pling means having a play with upper and lower limits comprising a small fraction of t at useful range of movement of said rough adji, ing member to allow of independent movers of said fine adjusting member within said and only within predetermined narrow limits at the range of movement of said rough adjusting member, substantially equally for ali positions at said rough adjusting member, an actuating memit her for said rough adjusting member, and scale means cooperating with said actuating member to indicate the position thereof.

11. In an adjusting device for a variable can denser or the like, a rough adjusting member having a useful range of movement of 180 an lar degrees, a fine ccupl members, said coupling means having with upper and lower limits comprising 10 angu lar degrees or less to allow of independent movement of said fine adjusting member within s limits and only within predetermined new limits of the range of movement of said rel adjusting member, substantially equally to positions of said rough adjusting me;

her, and scale means cooperating with ac ating member to indicate the position there 12. In an adjusting device for a variable denser or the like, a rough adjusting ment having a predetermined useful range of ment, a fine adjusting member, coupling s between said rough and fine adjusting members, said coupling means having a play with up, and lower limits comprising a range of 18th or less of the useful range of movement of roughadjusting member to allow of independent movement of said fine adjusting member w u said limits relative to and only within predeteni5 mined narrow limits of the range of more: of said rough adjusting member, subst' equally for all positions of said rough member, an actuating member for said 2'" Y adjusting member, and scale means cooper: therewith to indicate the position thereof.

13. In an adjusting device for a v denser or the like, rough adjusting napalm, adjusting means, a common actuating met for both said adjusting means, coupling between said actuating member and said adjusting means having a play with upper r lower limits comprising a small fraction. of total useful range of movement of said rou adjusting means, a frictional coupling 002 between said actuating member and su adjusting means to allow of indepen ment of said fine adjusting means limits and only within predetermined limits of the range of movement of said i adjusting means substantially equally for ail sitions of said rough adjusting meet 14. In a device as claimed in a means of said actuating a means cooperating therewith to indicat sition of said actuating mem 

